1. Field of the Invention
The present invention relates to a circuit breaker extraction device and, more specifically, to an interlock assembly having components on both the circuit breaker cell and the extraction device which are structured to prevent the circuit breaker from being removed from the cell unless the cell and the extraction device are locked together.
2. Background Information
Large circuit breakers are typically disposed in an enclosure or housing assembly. The circuit breaker, which may weigh as much as 1000 lbs., is typically disposed on a set of rollers, or a circuit breaker frame having rollers. The rollers are structured to engage a pair of rails extending from the front to the back of the housing assembly. The rollers and/or the housing assembly rails typically include a break or similar device structured to prevent the circuit breaker from moving. In this configuration, the circuit breaker may be inserted and removed from the housing assembly with little difficulty.
The circuit breaker, being heavy, is typically removed onto a movable cart, or a pallet that may be lifted by a hand truck, so that the circuit breaker may be further transported. Typically, the cart or pallet includes a pair of rails that are structured to align with the housing assembly rails. This type of cart is identified as an extraction device. Generally, the extraction device is placed in front of the housing assembly with the extraction device rails aligned with the housing assembly rails and with the extraction device brakes set. The circuit breaker roller brake is released and the circuit breaker is rolled out of the housing assembly onto the extraction device rails. Once the circuit breaker is on the extraction device, the circuit breaker brake device is reset and the extraction device brakes are released. At this point, the circuit breaker may be transported on the extraction device. Installation of a circuit breaker is essentially the same procedure in reverse. It is further noted that the housing assembly may be structured to hold a circuit breaker at a height above the floor, for example, some housing assemblies hold two or more circuit breakers in a stacked configuration.
The disadvantage to this system is that a circuit breaker may be removed when no extraction device is present or when the extraction device is not properly aligned. That is, it is known that technicians may simply release the brakes on the circuit breaker and pull the circuit breaker from the housing assembly while relying on their strength to support the circuit breaker. Technicians are also known to manually lift a circuit breaker to install the circuit breaker in a housing assembly. This procedure, especially when performed by a single person, is likely to cause injury to the technician and damage to the circuit breaker. There is, therefore, a need for an interlock assembly structured to operate between the circuit breaker housing assembly and extraction device that is structured to prevent the removal or installation of a circuit breaker from a housing assembly without an extraction device. There is a further need for an interlock assembly that locks the extraction device to the circuit breaker housing assembly.